1. Key Laboratory of Atomic and Molecular Physics and Functional Materials of Gansu Province, College of Physics and Electronic EngineeringNorthwest Normal University Lanzhou China
2. Department of PhysicsLanzhou University of Technology Lanzhou China
3. School of Physics and Information EngineeringShanxi Normal University Linfen China
4. School of Atmospheric PhysicsNanjing University of Information Science and Technology Nanjing China